1. Predicting Reaction Products
Chapter 9
Predicting Reaction Products

2. 1. Single Replacement Reactions
Single Replacement Reactions occur when one element replaces another in a compound.
A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-).
element + compound compound + element
A + BC  AC + B (if A is a metal) OR
A + BC  BA + C (if A is a nonmetal)
(remember the cation always goes first!)
When H2O splits into ions, it splits into
H+ and OH- (not H+ and O2- !!)

3. Single Replacement Reactions
Predict the products of the following reaction:
Aluminum metal reacts with aqueous hydrochloric acid (HCl).
Al(s) + HCl(aq) 
Al(s) + HCl(aq)  AlCl3(aq) + H2(g)

4. Practice
Al + Sn3P2 →
Cr(NO3)3 + Pb →
F2 + Na2O →
Na + water →

5. 2. Double Replacement Reactions
Double Replacement Reactions occur when the cations in two compounds switch places.
compound + compound  compound + compound
AB + CD  AD + CB

6. Double Replacement Reactions
To build your two new compounds switch the cations. Check ion charges to build neutral compounds and write the cation first.
Example:
AgNO3(aq) + NaCl(s) 
Another example:
K2SO4(aq) + Ba(NO3)2(aq) 
AgCl(s) + NaNO3(aq)
KNO3(aq)+ BaSO4(s)

7. Practice HCl + AgNO3  CaCl2 + Na3PO4  Pb(NO3)2 + BaCl2 
FeCl3 + NaOH 

8. 3. Decomposition Reactions
The simplest decomposition reactions occur when a binary compound breaks up into its elements.
Compound  Element + Element
In general: AB  A + B
Example: 2 H2O  2H2 + O2
Example: 2 HgO  2Hg + O2

9. Decomposition
PbO2(s) 
AlN(s) 

10. Practice
Mg3P2 →
LiCl →

11. 4. Synthesis reactions
The simplest Synthesis reactions occur when two elements combine and form a binary compound.
element + element  compound
Basically: A + B  AB
Example: 2H2 + O2  2H2O
Example: Fe + Cl2  FeCl2

12. Synthesis
Na(s) + Cl2(g) 

13. Practice
Mg(s) + F2(g) 
Al(s) + O2(g) 

14. Combustion
Combustion reactions combine a hydrocarbon with oxygen to produce carbon dioxide and water.
C5H12 + O2  CO2 + H2O

15. Practice
C10H O2 
C12H22O11 + O2 

16. Predicting the Products of Reactions – In Class Examples (In Notebook)
HgO  Hg + O2
Al + Pb(NO3)2  Pb + Al(NO3)3
K + water  H2 + KOH
N2O5  N2 + O2
PbCl2 + Li2SO4  LiCl + PbSO4

17. Predicting the Products of Reactions – In Class Examples
Cl2 + LiI  LiCl + I2
H2 + O2  H2O
AgNO3 + K2SO4  KNO3 + Ag2SO4
CH3OH + O2  CO2 + H2O
Pb + Cu(NO3)2  Cu + Pb(NO3)2 or Pb(NO3)4

18. Predicting the Products of Reactions – In Class Examples
C3H8 + O2  CO2 + H2O
MgBr2 + FePO4  Mg3(PO4)2 + FeBr3
Li2S  Li + S
K + Br2  KBr

19. Homework
“6 example problems” (on the back of Prediction of Reaction Products – In Class Examples).